Gypsum-tile machine



Oct. 19 1926.

J.G.JOHNSTON GYPSUM TILE MACHINE Filed June 23] 1924 4 Sheets-Sheet loct. 19,1926. 1,603,917

J. G. JOHNSTON GYPSUM TILE MACHINE Fle'd June 23. 1924 4 Sheets-Sheet 3Patented Oct. 19, 1926.

JOHN G. JOHNSTON, OF LOS ANGELES, CALIFORNA, ASSGNOR TO `PACIECGYIES'UlI TILE COMPANY, A CRPORATON.

.GYPSUM-TILE MACEINE.

Application filed June 23,

This invention has to do generally with molding machines and is moreparticularly concerned with machines for molding gypsum tile and thelike, such as are used in the construction of tireproof partitions andwalls.

' 'I will describe the invention as embodied in a machine designed forproducing hollow tile of the type set forth in my co-pending applicationfor United States Letters Patent on building blocks and wallconstruction, tiled Decemberl, 1923, Serial No. 681,496; but thisdescription of a particular embodiment is not to be construed as in anyway indicating that the invention is limited to this specificapplication for the machine may be utilized for molding blocks of anysuitable plastic substance such as concrete or clay, and, by makingchanges of a minor nature, it is adapted to turn out solid tile orblocks of exterior configuration other than that illustrated in lsaidco-pending application.

It is necessary that the mold plates be stripped from the sides of theformed block before the plastic substance has taken its final set (theiinal set usually taking piace within a dry kiln where all sides of theblock must be exposed) and it has been found of eXtreme diiiiculty toperform this stripping operation without tearing away portions o theunset substance, breaking away the corners or defacing the sides of theblock to such an extent as will render them unserviceable, or at best,unsightly. Therefore, it is among the objects of my invention to provide a molding machine which will admit of stripping without damagingthe block in any way.

I also provide means whereby the mold plates may be moved positively andeasily to and from operative positions (that is, to and from positionswhich pl ace the molds in condition' to receive a charge of material)and since a battery of molds is preferably provided in connectionwitheach machine, l inter-connect the mold plates of the various unitsso they may be moved simultaneously, with little effort, and with speed.

To form the facial depressions provided in the tile under particularconsideration, I provide the inner faces of the mold plates withresilient conical core buttons arranged with their bases out so theplastic material, entete the mold, :flows around the. but

192i Serial No. 721,744.

a manner to leave the depression mouths of restricted diameter, whereby,during wall construction, mortar spread on the abutting faces ofadjacent blocks enters the depressions and forms dove-tail' keyconnection therewith. Due to the coinpressible characteristics of thebuttons, their enlarged heads may be withdrawn through the restrictedmouths of the facial depressions during mold stripping operation withouttearing the over-hanging mouth defining walls.

l also provide means for looseningtt-he cell forn'iing cores from thetile,` sosaid tile may ie easily lifted free yof the mold for transferto kiln cars. This is an especially important feature in connection withthe manufacture of hollow1 tile having their medial cells closed otfwith a top wall. In such cases, the cores are entirely surrounded bygypsum except at their lower ends, and considerablc effort must beexerted to break the vacuum caused by drawing the tile and core apartafter the gypsum has taken its initial et. However, i havearranged'means for moving the cores without calling for undue effort onthe part of the operator, and without chipping or breaking away thewalls of the sen'ii-plastic tile.

Other objects and features ofthe invention may be pointed out to betteradvantage in the following description, reference, being had to theaccon'ipanying drawings, in which: i

Fig. 1 is a diagrammatic side elevation of my machine in position toreceive a charge of plastic material;

Fig. 2 is a side elevation of the machine, certain parts being brokenaway to more fully disclose underlying parts;

Fig. 3 is a top plan view of the machine, the cover plate or tray beingbroken away from the left'side of the view to expose the mechanismtherebeneath Fig. l is an end elevation of. the machine as viewed fromthe left of Fig. 2;

Fig. 5 is a horizontal section on line 5 5 of Fig. 2; but showing themold plates moved out of operative position; n

6 is an enlarged vertical section on the broken line 6 6 of Fig. 2;

-Fig. '7 is a horizontal section on; broken line 7T of Fig. G;

preferred type of joint between an adjustment stud, end plate, and endplate supporting member Fig. 9 is a contracted, fragmentary section. online 9 9 of Fig. 4t;

Fig. 10 is a horizontal section on line 1O1OA of Fig. 9;

Fig. 11 is a vertical section on line 11-11 of Fig. S). showing the coretrip mechanism, but omitting all mechanism therebeneath;

Fig. 12 is an enlarged detached elevation of the main bracket shown atthe right of Fig. 2; y Y

Fig. 18 is an elevation of the bracket as viewed from the right' of Fig.12;

Fig. lei is an enlarged, fragmentary section on line lll- 14C of Figzt;

Fig. 15 isr an enlarged section on line 15-15 of Fig. 7, showing abutton or core for forming recesses in the sides of the linished tile;

Fig. 16 is a perspective view of a tile such as the illustrated machineis designed to turn out, but is not to be considered as indicating thatthe invention is limited in its application to a machine for turning outonly tile of the illustrated configuration; and.

Fig. 17 is a longitudinal, medial section through a `tile of theconfiguration illustrated in Fig. 16.

Before proceeding to a detailed description of the machine, I wish tomake certain general remarks and reservation-s.

lVhile it is obviously of economic advantage to provide a. battery ofmolds in a single machine and to provide mechanism for simultaneouslyshifting the plates of the several moulds into and out of operative p0-sition, the general principles of construction and operation may beapplied to a single mold; that is, the invention does not lie alone inthe provision of inter-connecting means between the several mold unitsof a battery machine.

Again, I have illustrated the machine as being mounted on a track guidedtruck, so it may be moved to bring the several molds successivelybeneath the material distributing spout and then moved clear of thematerial mixer and distributer for the stripping and tile removaloperation.v However, it obviously lies within the scope of certain of myclaims to provide a stationary machine and convey the plastic materialin buckets, or the like, to the machine, or to swing a movabledistributor over the several molds so they may all be charged froml astationary mixer.

In certain of the drawings, notably Fig. 2, the scale is necessarily sosmall that I have broken away certain parts in order to more fullydisclose underlying elements. Thus, in Fig. Q, although each end plateof the mold is provided with a supporting member attached at top andbottom to anglie irons, the showing of these end plate supports wouldmerely confuse the showing of the side plate actuating mechanism.Therefore, I have omitted these end plate supports, except between thebroken lines c, Z); and between these lines I have omitted all sideplate supporting and actuating mechanism. For the same reason, the angleiron connecting the bottom ends of all end plate supports is shown onlyfragmentarily.

.I will first describe the type of tile which the illustrated machine isdesigned to turn out, it being borne in mind that the invention, in itsbroader aspects, is readily applicable to machines for the manufactureof tile of different conformation.

Referring to Figs. 16 and 17. the rectangular hollow tile A has sidewalls 10, end walls 1l, and top wall 12. This construction leavesinterior air spaces or cells 14, separated by vertically extendingpartition 15, opening only at the lower face of the tile. The side andend walls are provided with facial depressions lti which are preferablyof closed contour in contra-distinction to channels which might extendfrom top to bottom of the walls. The closed contour characteristics ofthe depressions preclude the withdrawal of the mold plate (which supportthe depression forming cores) in any direction but perpendicularly tothe side or end walls ot the tilel In other words. the mold plates andtile may not have relative vertical movement until the depressionforming cores have been moved out of engagement with the tile. Thispoint will be more apparent after the hereinafter detailed discussion ofthe mold plates and their depression forming cores, but has beenmentioned above to clearly set out the necessity of moving the moldplates horizontallyY before the tile may be removed from the mold.

i 'lhe mouths v1"( of the depressions are restricted with respect to theinside diameter of the depression bores. This gives a conical ordove-tail outline to the recesses, as viewed in axial cross-section. andforms sockets for receiving mortar spread between adjacent tile in wallconstruction. The mortar thus entering the sockets fills the recesses ordepression. and when set, forms outwardly flaring or in ellect, headedstuds or protuberances) for n'iechanically interlocking the tile andmortar.

In Fig. 2, I have shown a truck 18. comprising angle iron sills 1) and2O joined by end bed plates 21 and 22; intermediate bed plates or moldbase-1 Q23: and axles Q41-, which are journaled in sill supportedhangers 2G. the axles carrying wheels 2T whereby the truck may be guidedfrom point to point over track 28. Truck 1S carries plurality ot molds29 but since all these molds may be of identical construction. I needdescribe but one in detail.. The mold walls are made up of vertical sideplates and 31, and end plates 32 and 33, all of these plates being somounted that their lower edges closely approach, or, j ireferably, bearon and are movable over an associated mold base plate 23, the latterserving to define the bottom edge of the tile to be molded. The sideplates are movable towards and away from each other, as are also the endplates, andthe side plates preferably over-lap the end plates when themold is contracted, as shown in Figs. 2 and 7. l'Vhen the side and endplates are at their limit of approaching or inward movement, they, withtheir associatedbase plates, define a chamber 34 ofrectangular outline,the dimensions of the chamber being the same as the over-all dimensionsofthe block or tile to be molded. lVhen moved to occupy this relativeposition, the plates may be considered as in operative position` and themold may, be considered as contracted When the plates are moved awayfrom each ether, as indicated in Fig- 5, they may be considered as outof operative position, and the mold, proper, may be considered asexpanded.

New, let us .Consider the mountings of the plates and the mechanismwhereby they are moved to and from operative position, it beingunderstood that they are. moved from operative position to strip themfrom the exterior of the partially set tile.

Bed plates 21 and 22 each carry a pair ofy brackets (see Figs. 12 and 13for details thereof) those on plate 21 being indicated at 35 and thoseon plate 22 being indicated at 36. Each bracket has a pair of verticallyspaced bearings 37, 38, through which eX- tend slide rods 39 and 40.These rods extend longitudinally of the truck, that, is, from onebracket 35 to a companion bracket 36. A supporting member 41 is fixed onrod 40 and is adjustably secured to the inner side of plate 3 0 at 42,while supporting member 43 is fixed on rod 39 and is adjustably securedto the inner side of plate 31 at 44. The adjustable connection betweeneach plate and its supporting member is in the form ofY a threaded stud45,. lixed to the support and passing' throughv the associated plate,nuts 46 serving to lock the plate in adjustment. Obviously, byadjustment of connections 42 and 44, the horizontal distance betweenside plates may be varied for the purpose of varying the width of themold chamber or for bringing the side plates into proper associationwith their end plates when the mold is contracted.

Considering all the side plates of the machine, it will be noted thatalternate plates are attached to a given slide rod, and consequently.that opposite longitudinal movement of the two rods causes the oppositeside, plates, each mold to move towards or away from each other and itwill be noted that thev plates remain erect` and parallel during suchn'iovement. I employ the following mecliainsm for thus moving the platesinto or out of4 operative position. A transverse rock shaft 46, isarranged at each end of the machine, the shaft being journaled withinbearings 47 on brackets 35` and 3 6. @ranks 48 are secured near the eX-tremities of each rock shaft and the ovppo; site and equi-length crankarms are attached, with suitable lost motion connections, to rods 39 and40. The ends of the shaft may be squared or otherwise mutilated toreceive a wrenching tool whereby the shaft may be rocked to causehorizontal reciprocation of the slide rods.

I iind, however, that with the arrangement just described, it issometimes diflicultl to secure sufficient leverage to enable theoperator to easily reciprocate the rods, especially in view of the factthat the depression forming cores (to be described) which I employ onthe side plates, and which are embedded in the sides of the tile, offerconsiderable resistance to separative movement between the plates andtile. Therefore, I prefer to compound the leverage in the manner shownin Fig. 2. A crank arm 4.9 is secured to one rock-shaft 48, and link 50connects thisarm to lever 51, the latter being pivotally mounted on thesill-carried stub shaft 52. Lever 5,1 carries horizontally projectingpins 53 whereby a crow-bar 54, or the like, may be inserted between thepins in thef manner rillustrated in dotted lines in Fig. 2, and used toswing lever 5 1. The swing of lever 51 andits associated mechanismcauses reciprocation of: rods 39 and 40 and brings about a consequentmovementof side-plates 30, 31 into or out of operative position.

I will now describe the mounting and actuation of end plates 32, 33. Atthe upper extremity of each bracket 35, 36, are the bearings, 56, eachaxially alined pair of which support slide rods 57,58. Rock shafts 5 9extend through bed plates' 21 and 22, being journaled in bearings 60 andextending vertically midway between slide rods 57, 58. Cranks 61 arefast on the rock shaft, and the crank arms have suitable lost motionconnection with the slide rods, so oscillation of the shaft(accomplished for instance, by the application of a suitable wrenchingtool to the squared or mutilated shaft ends) imparts reciprocatorymovement to the slide rods. At the lower ends of shaft 59 are cranks 62(Figs. 2 and 4) which are connected by reach rod 6,3, so oscillation ofone vertical shaft causes coincident oscillation of the other. f

Intermediate the plates 20, 21 and cranks 61, are the shaft' carriedcranks 64, similar to cranks 61.. ,lhe opposite extremitiesflef Cal LIL

`wardly away from the mold center.

cranks 64 are connected by links 65 and 66 to lower side rails 67 and68, respectively (see Figs. 2 and 4).

Slide rods 57 and 58 are fixed to the opposite extremities of upper siderails 69 and 70, respectively, and these rails (preferably, they areangle irons) overlie and substantially parallel sills 19 and 20.Supporting member 71 Figs. 2, 6 and 8) are secured to rails 69 and 7()at 72, and the odset legs 73 of said members are secured to end plates32 and 83 at 7-1. By reason of the offsets, side plates 30, 31 mayextend beyond end plates 32, 33 to allow for the attachment of supportmembers Ll1 to the sides of plates 30, 31, while rails 69, 70 are spacedhorizontally a sufficiently greater distance than are end plates 32, 33,to bring about certain desired relative positions between said rails andassociated mechanism.

Preferably, lower side rails 67 and 68 are adjustab-ly attached to endplates 32, 83, and

support member 71 in the manner illustrated in Figs. 6 and 8. Flat headscrews 75 extend through the end plates from the insid,e of the mold,the screw heads resting in counter-sinks so their tops are flush withthe plates, and the screw shanks are threaded through and project beyondmember 71. One end of each stud 76 has an internally threaded bore 77for receiving the projecting end of given screw 75, while the oppositeend of the stud is externally threaded and extends through one of thelower side rails. Nuts 78 are threaded on studs 76 at opposite sides ofrail 67 or 68 and serve as means for adjusting and locking the lowerends of the mold plates 32, 33 in adjustment. Thus, by propermanipulation of nuts 78, the end plates may be shifted to vary thelength of the mold compartment somewhat, or to bring said plates intoparallelism should they become somewhat displaced.

It is evident that reciprocation of slide rods 57 and 58 (during a givencrank movement they will, of course, move horizontally in oppositedirections due to the central arrangement of shaft 59) causes rails 67and 69 to move horizontally towards or away from rails 68 and 70,respectively, and move end plates 32, 33 inwardly towards or out- Theend plates remain erect and parallel during their movement. Thus,counterclockwise movement of either shaft 59 t as viewed in Fig. 3)moves the end plates away from each other and out of operative positionV(see Fig. 5) while subsequent opposite rotation of the shaft will drawsaid plates back to operative position. By reason ofthe two pointapplication of force on each end plate, strains are distributedthereover, and the plates are moved to and fro with ease and are pulledevenly from the molded tile rather than becoming canted as they arewithdrawn.

The inner faces of the mold plates are studded with core buttons 79 (seeFigs. 6, 7 and 15). These buttons are for the purpose of forming facialdepressions in the finished tile, as described above. They are made ofresilient, compressible material such as rubber, and are molded aboutstuds 8O which are threaded into suitable apertures in the mold plates.lreferably, the buttons are in the form of truncated cones or arepreferably of frusto-conical outline7 their lower bases facing outwardlyfrom and their upper bases contacting with the mold plates. ln order toincrease their yield ability to compressive forces, the lower bases ofthe buttons may be recessed at 81, as clearly shown in Fig. 15.

Assuming' that the mold plates are in operative position.y when gypsumin 'a plastic state is admitted to mold chamber 34 it flows around corebuttons 79, leaving hollows in the sides of the gypsum body, thesehollows or depressions being of dove-tail, axial crosssection, or inother words, complementary in outline to buttons 79. Then, after thegypsum is partially set and when the mold is expanded, the buttons areradially compressed as they pass out through the restricted mouths -v ofsaid depressions, the buttons yielding inwardly rather than tearing awaythe overhanging lips of said mouths. As soon as the buttons are entirelyclear of the gypsum body they return to normal shape due to the inherentresilient qualities thereof.

New referring to Figs. 2, 3 and 6, I have illustrated a tray 82 hinged'at 83 to brackets 35 and 36 so the bottom plate 84 of said tray may belowered onto or lifted clear of the molds. Plate 84 serves as a coverplate for the machine and has apertures 85 which register with chamberswhen the tray is lowered over the contracted molds, yand said plate hasa marginal, upturned Hange 86 (preferably formed by riveting` anoutlining angle iron to the top of plate 84.) lVith the molds and trayin operative position, plastic gypsum may be poured over the trayanywhere within the limit established by flange 86, and then spread soit runs into compartments 34- and fills the molds. lt will be noted byreference to Fig. 3 that llange 86 is horizontally spaced from the topedges of the mold plates when the latter are in operative position. Thecover plate keeps the `gypsum from dropping between molds, and forms agage plate for establishing the height of the finished tile, since thegypsum, after it has partially set, is scraped of'f flush with the topface of said plate, the horizontal spacing of flange 86 making thisscraping operation one of easy accomplishment.

f I will new discuss the cell cores and their actuating mechanism,referring particularly to Figs. 6, 9, 10, 11 and 14. In order to providethe previously described cellular construction, I arrange twohorizontally spaced, hollow cores 87 in each compartment 34. These coresare adapted to project downwardly through apertiues 88 in base plates23, the cores resting on and being secured at 89 to vertically movableangle iron sills 90 which extend longitudinally beneath base plates 23and in substantial parallelism with the truck sills. Sills 90 may beconsidered as making` up a core supporting frame. The two coresoccupying each chamber 34 may be tied together by plate 87a (Figs. 5 and6) which is located below bar 23 of said plate 23, said bar forming thepartition between the core accommodating apertures 88.

The opposite extremities of sills 90 are connected to the truck by links91, 92, These links have pivotal connection at 9S with cranks 94 and 95respectively, said cranks being lixed to transverse shafts 96 and 97journaled in hangers 98, the latter depending from truck sills 19, 20.,Shafts 96 and 9,7 also 'carry lixed crank arms 99, said arms beingconnected by link or reachrod 100. y

At the end of shaft 96 is an actuating levei` 101 whereby the shaft maybe rocked, the crank and link connection 99, 10'0 causing-cd incidentoscillation of shaft 97. It is obvious that clockwise rotation of shaft96 (as viewed in Fig. 9) swings cranks 94, 95 in the same direction andallows gravitation of or exerts a. downward pullf on sills 90 and theirassociated cores 87. Subsequent counterclockwise movement of shafts 96,97 and cranks 94, 95, lifts the sillsyin a manner to return the cores toyoperative position, the contact of plates` 67a with partition bars 23positively establishing the limit of upward movement of the cores. y

In order that sills 90 may not have longitudinal movement during theirascension and descension, I secure depending [stop Vblocks 102 to thelower faces `of bed plates 21 and 22, and sills 90 carry angle ironstops 103 which have sliding engagement withv opposed sides of blocks102 during sill movement. y

I may provide various'means for release ably locking the cores inoperative or raised position. p range an angle iron stop 104 on theinner face of actuatingY lever 101, (see Fig. 14) and a lock bar 105,either pivot'ally and independently mounted on stub shaft 52 or made asan integral extension of Vlever 51. Assume that bar 105 be loose onshaft 52. When the cores are in operative position, lever 101 occupiessuch ay position vthat bar 105 may be swung into engagement with stop104, the horizontal leg` of said stop preventing the bar fromdropping,land the end of the bar engaging the vertical leg of said As apreferred type of lock, I arstop to prevent counterclockwise movement oflever 101 andshaft 96, as viewed in Fig. 14, or clockwise movementthereof 'as viewed in Figs. 2 and 9. By the prevention of such shaftmovement, cranks 94, and links 91, 92 are held stationaryand preventgravitation of the sills and cores, it being understood that when saidsills are at the limit of Atheir upward movement the pivotal connectionsbetween sills, cranks, links and shafts are so relatively located thatthe sills may not gravitate by forcing counterclockwise movement ofcranks 94,95, as viewed in Fig. 9.

By making bar integral with lever 51, I may provide an interlock betweenthe side plate actuating mechanism and core moving mechanism. In such asituation, shaft 96 may not be rocked to lower the cores until lever51'has beenk rotated sutliciently to lift bar 105 clear of stop 104,thus compelling se'parative movement between the mold side plates 30, 31before the cores 87 may be lowerec.

Since it requires considerable effort to start the cores away from thetile, it being obvious that vacuum created between them during theirseparation must be broken, I have provided automatic means for startingthecores, As will be seen, I take advantage of the veryconsiderableweight of the tile lilledmold car to accomplish this end.

y Pivoted on axles 24 and 25, respectively, are the trip lingers orVlevers 106 and 10621, which are pivotally connected to cross bars 107,the latter being suspended from sills 90 by links V10S. The lingers, asviewed from the ends of the truck, are out of alinement, and are adaptedto simultaneously engage inclined ramp rails 109 andlll-O (these ramprails being positioned between the track rails 28, one of the rampsbeing in vertical alineinent with one linger, and the other ramp beingin vertical alinement with the other finger when the truck is movedthereover). rlhe lingers, in riding over their respective ramps, areswung in a clockwise direction, (as viewed in Fig.,9, and assuming, ofcourse, that lock bar 105 has previously been moved upwardly fromengagement with stop 104) thus exerting a downward pullon links 108 andmoving the cores clear of the newly formed tile. The cores aresubsequently reset in operative position by proper actuation of lever101.

Now assume the mold car yis in the condition of Fig. 1, that is, themold plates, coresv and tray are in operative position, and the chambers84 ready to receive a charge of gypsum. Truck 18 is run beneath the distributing spout 111 which leads from theelevatedgypsum mixer 112. lTheplastic gypsum is allowed to flow in to tray 82 whence it spreads andl'lows to and fills chambers 84,

the car preferably being moved to bring an empty chamber1 beneath spout111 as a given chamber becomes full (rather than delivering all thegypsum at one point along tray 82 and spreading it the length of the carby means of a troivel or the like). The operator admits sutlicientgypsum to insure a complete filling of all molds, and then pushes thecar along track 28, clearing the Way for an empty mold car. After thegypsum has partially set, the surplus material is scraped from 0E plate84. Tray 82 is then swung upwardly and back on hinges 83, and the sideand end plates ot the mold are stripped trom the tile as previouslydescribed. Cores 87 serve to hold the tile against displacement duringthis stripping operation, for they prevent said tile from adhering toand moving with any one plate.

Lock bar 105 is then disengaged from stop 104, and the car pushes overramps 109 and 110 (or lever 101 is manually rotated) to pull the coresaiv y from the tile. Thereupon the operator lifts the tile out otcompartments 34 and places them on a lnln truck. The empty mold car isnon7 cleansed, the inner faces ot the mold plates are lubricated toprevent adhesion ot gypsum, the en tire mold placed in operativecondition, and the car returned to a position beneath spout 111 readyfor a neiv charge.

It will be understood that While I have shown and described a preferredembodiment ot my invention, various changes in structure, arrangementand design may be made Without departing from the spirit and scope ofthe invention. Therefore, l do not Wish to be limited to the particularembodiment shown and described, except for such limitations as a fairinterpretation ot the appended claims may impart.

Having described a preferred form of my invention, I claim:

1. In a molding machine, a plurality of movable vertically arranged moldplates adapted, when in operative position, to detine the sides o't amold chamber, means for moving the mold plates into and out of operativeposition, and a cover plate hingedly movable to and trom a position oversaid mold plates and having apertures adapted to register with said moldchamber when the mold plates are -in operative position.

2. In a molding` machine, a plurality of movable, vertically arrangedmold plates adapted, when in operative position, to detine the sides ota mold chamber, means tor moving the mold plates into and out ofoperative position, and al tray movable to and trom a position over saidmold plates, the bottom ot the tray having apertures adapted to registerWith said mold chamber when the mold plates are in operative position,and the sides ot the tray being horizontally spaced trom the mold platesWhen said plates are in operative position.

3. In a molding machine, a supporting frame, slide rods supported by thetrame, mold plates, adjustable connections between the rods and plates,and means for sliding the rods in a manner to move said plates withrespect to the supporting trame.

4. In a molding machine, a supporting trame, a pair ot slide rodssupporte-d by the trame, a pair of oppositely disposed mold plates, oneot the mold plates being connected to one of the rods and the other moldplate being connected to the other rod, and means for reciprocating therods to change the relative positions ot the plates.

5. ln a molding machine, a supporting trame, a pair ot slide rodssupported by the frame, a. pair ot' oppositely disposed mold plates, oneot the mold plates being connected to one ot the rods and the othermold.

plate being` connected to the other rod, and means :tor simultaneouslyreciprocating the rods in opposite directions whereby the mold platesare simultaneously moved toward and away from each other.

6. The combination ot a truck adapted to be rolled over a predeterminedpath, a plurality ot' plates on the truck adapted to define a moldchamber, a movable core supported by the trame and adapted to be movedinto and out or" operative position Within the chamber, core movingmechanism on the truck, and means arranged in the path of the truck andadapted to coact with said mechanism in a manner to operate it when tbetruck is moved therepast.

7. The combination ot a truck adapted to be rolled over a predeterminedpath, a mold element on the ytruck and movable into and out oitoperative position, element moving mechanism on the truck, and meansarranged in the path ot the truck and adapted to coact with saidmechanism in a manner to operate it When the truck is moved therepast.

8. The combination of a truck adapted to be rolled over a predeterminedpath, a plurality of plates on the truck adapted to deline a moldchamber, a movable core supported by the :trame and adapted to be movedinto and out ot operative position Within the chamber', core movingmechanism on the truck, and a ramp rail positioned in the path of saidtruck and adapted to coact with said mechanism in a manner to operate itwhen the truck is rolled thereover.

9. In a molding machine, a supportinof frame, a plurality ot mold platessupported by the trame and movable into and out ot operative position,means for moving the plates, a core supported by the frame and movableinto and out ot operative position between theplates, means for movingthe core, and releasable means interlocked With the plate moving meanstor locking the core in operative position.

10. In a molding machine, a mold plate, and a compressible core securedto the plate, said core being in the form ot a truncated cone arrangedbase out.

11,. In amolding machine, a mold plate, a core secured to the piate andhaving an enlarged head projecting from the side of said plate, saidhead being compressible and resilient and having a recess in its ends.

l2. In a molding machine, a supporting `frame, a pair of slide rodssupported by the i'rame, a pair or' oppositely disposed mold plates, oneof the mold plates-being connected to one of the rods and the other moldplate being connected to the other red, and means for reciprocating therods te change the relative positions of the plates; said meansincluding a rock shaft journaled on the frame, and a crank on the shankand having a pair of arms extending oppositely therefrom, and connectednear their free ends, one to each rod.

13. In a molding machine, a supporting trame, a pair of slide rodssupported by the rame, a pair ot oppositely disposed mold plates, one ofthe mold plates being connected to onevof the rods and the other moldplate being connected to the other rod, and means 'for reciprocating therods to change the relative positions of the plates; said meansincluding a rock shaft `iournaled on the trame, a crank on the shaft andhaving a pair of arms extending oppositely therefrom and connected neartheir tree ends, one to each rod, and a crank and link mechanism :forrocking the shaft.

14. The combination o' a relatively movable truck adapted to be rolledover a predetermined path, a mold element on the truck and movable intoand out of operative position, element moving mechanism on the truck,and relatively stationary means arranged to be traversed by the truck inits movement over said path and adapted to coact with said mechanism ina manner to operate it When the truck is moved therepast.

In Witness that I claim the foregoing I have hereunto subscribed my namethis 27th day of May, 1924;.

JOHN G. JOHNSTON.

